The present invention relates to an arrangement in incinerator in which fuel is burned in a fluidized bed of refractory particles and the fluidizing air is supplied from a windbox through a constriction plate which carries the fluidized bed
In incinerators operating with a fluidized bed of refractory particles, e.g. sand, pipe coils are often used in the fluidized bed for the circulation of a coolant for cooling the bed. If the circulation of coolant fails, the pipe coils may burn out. A burning out of the coils, the tuyeres or other members arranged in the incinerator may also occur if for other reasons the temperature of the bed should become excessive.
The object of the present invention is to provide an arrangement in incinerators of the above mentioned type which allows the incinerator to be rapidly put out of operation and at the same time protects costly and sensitive elements of the incinerator from the residual heat in the fluidized bed.